RECORD: Darwin, C. R. 1838. [Notes on Cocos-Keeling Islands plants]. In J. S. Henslow, Florula Keelingensis. An account of the native plants of the Keeling Islands. By the Rev. J. S. HENSLOW, M.A., Professor of Botany in the University of Cambridge. Annals of natural history 1 (July): 337-347. 2 pls.

XXXVII.—Florula Keelingensis. An Account of the Native Plants of the Keeling Islands. By the Rev. J. S. HENSLOW, M.A., Professor of Botany in the University of Cambridge.1

THE Keelings consist of small coral islands, ranging in a circle, and inclosing a lagoon or salt-water lake of nine and a half miles in its longest diameter. They lie in lat. 12° 5' 8,, and long. 90° 55' E., very nearly 600 geographical miles to the S.W. of Java Head or the Straits of Sunda. They stand apart from any other group or archipelago, and the naturalist is curious to learn the character of their productions. Mr. Darwin, who accompanied the Beagle in her late voyage round the world, visited these islands in 1836, and is about to give an account of their geological conditions,2 as well as of the scanty zoology which they furnish. As he obligingly presented me with the plants which he collected, together with his memoranda respecting them, I have thought that a list of the species, accompanied by a few remarks, might be of interest; and chiefly as serving to point out a set of plants whose seeds must be provided in a very eminent degree with the means of resisting the influence of sea water. For the satisfactory determination of the geographical distribution of species, it is necessary to be extremely careful in discriminating the species and even varieties which occur in different regions, and I have therefore generally added a few remarks on the state of the individual specimens in question, that every one may form a better estimate of the degree of probability of each having been correctly identified.

The largest of the islands is about five miles long and a quarter of a mile broad. Some sand hillocks on it are thirty feet in height, but the general level does not exceed six or eight feet. The foundation of all of them is a solid coral reef, which receives continued additions from fragments of coral and sand brought by the waves and wind. The soil is entirely

Another list that has not surfaced is that prepared for Henslow [by Darwin] of the Cocos-Keeling Islands plants. Many of those enumerated in Henslow's (1838) [i.e. the present paper] paper on Darwin's collections have comments on them attributed to Darwin. … This information is not in the Plant Notes or the Zoological Diary, leading me to conclude that it must have been in a separate list, probably prepared after the Beagle returned to England

243 words from Darwin's original list are quoted by Henslow. The islands were named after their discoverer Captain William Keeling in 1609. See Porter 1986.

composed of broken corals and shells, sometimes in the form of calcareous sand; and the quantity of vegetable mould is extremely small. Twenty-three of the islands bear trees; and there are many others of small dimensions, scarcely elevated above the surface of the ocean, which produce none. When first seen, nothing can be observed but a belt of cocoa-nut trees encircling the lagoon. The abundance in which these occur has tempted a respectable Englishman named Ross1 to bring his family and settle here. He has with him a party of about eighty Malays, who are employed in manufacturing cocoa-nut oil; and the nuts also are exported to Mauritius and Singapore. Thrown as these men are so completely upon their own resources, they have accurately investigated the natural productions of the islands, and readily pointed out to Mr. Darwin the different species of plants, and assured him that he had seen them all except one, of which there was only a single tree, bearing a large square and very hard nut, growing on one of the islands which he did not visit. Excepting the cocoa-nut, and one other tree which was not in flower, and which attains a diameter of five or six feet, with particularly soft wood, Mr. Darwin brought away specimens of all the species he saw, amounting to twenty-one.

From the character of the soil and the condition of the islands we might expect à priori to meet with a purely littoral flora, and with none but extensively sporadic species. Mr. Darwin heard of the trunks of trees, of many seeds, and of old cocoa-nuts being washed on shore from time to time, and probably all the species which have thus been introduced are to be found in the East Indian Archipelago, or on the neighbouring continent, though they have not all been noticed there. Two at least of the species appear to be hitherto undescribed, and one or two others possess an interest from their rarity, and the little information we possess concerning them; but all the rest have an extensive range throughout the intra-tropical regions.

Of the few imported plants the banana does not thrive well; the sugar cane has in some parts run wild, but has lost greatly in flavour, as also has the tobacco. Besides these a little maize and a few vegetables are cultivated. Three species

1 John Clunies Ross (1786-1854), a Scottish Merchant navy captain, settled in the islands of the Indian Ocean for the first time in 1827 and established cocoa-nut plantation. Darwin visited the islands in the Beagle 1-12 April 1836. These coral atolls with lagoons were an important influence on Darwin's views on the origins of coral islands.

of grass had been introduced, (Panicum......, Eleusineindica, and Poa plumosa,) as was stated, from Java, under an impression that goats would not eat the rank herbage of the island; but the settlers were surprised to find that one of these animals left on the islands by Capt. Fitzroy preferred the native to the imported species.

As the flora of the island of Timor, which lies nearly due west of the Keelings without any intervening land, has lately been described by Mons. Decaisne,1 I have placed a (T) in the following list opposite those species which he has recorded in his very excellent 'Herbarium Timorense.'

List of the Plants Indigenous to the Keelings.

MALVACEÆ.

CINCHONACEÆ.

1. Paritium tiliaceum, St. Hil. T.

11. Guettarda speciosa, Linn. T.

TILIACEÆ.

CORDIACEÆ.

2. Triumfetta procumbens, Forst.

12. Cordia orientalis, R. Brown. T.

LYTHRACEÆ.

BORAGINACEÆ?

3. Pemphis acidula, Forst. T.

13. Tournefortia argentea, Linn. T.

PORTULACACÆ.

ACANTHACEÆ.

4. Portulaca oleracea.

14. Dicliptera Burmanni, (var.?)

LEGUMINOSÆ.

Nees.

5. Guilandina Bonduc, Hort. Kew.

APOCYNACEÆ.

T.

15. Ochrosia parviflora.

6. Acacia (Farnesiana?) Linn. T.

GRAMINEÆ.

URTICACEÆ.

16. Panicum sanguinale, (var. ?)

7. Urera Gaudichaudiana, n. s.

Linn. T.

AMARANTHACEÆ.

17. Stenotaphrum lepturoide, n. s.

8. Achyranthes argentea (var. ?)

18. Leptuvus repens, Forst.

Lam. T.

PALMÆ.

NYCTAGINACEÆ.

19. Cocos nucifera, Linn. T,

9. Boerhavia diffusa, Willd. T.

MUSCI.

var. β. ?

20. Hypnum rufescens, Hooker.

var. γ. ?

FUNGI.

SCÆVOLACEÆ.

21. Polyporus lucidus.

10. Scævola Kœnigii, Vahl. T.

22. 23. Two trees of which no specimens were procured.

1. Paritium tiliaceum.—Leaves large, and the linear pore upon one to five of the nerves on the under side.

"Common on one of the islands. It is exceedingly useful throughout the Pacific; and in Otaheite particularly, the bark is employed in the manufacture of cordage, whilst the light wood is used by the fishermen for floats. The natives readily procure fire from the wood by friction."—C. Darwin.

2. Triumfetta procumbens. Forster, Prod. n. 204.2—This species is placed by De Candolle among those "non satis notae." By Mr. Brown's3 kindness I have satisfactorily iden-

tified it, by comparison with Forster's original specimens in the British Museum. As much uncertainty prevails respecting the number of species in the genus, I shall add a detailed description of the present specimens. Messrs. Wight and Arnott have observed, at page 74 of their Prod. Floraæ Indiæ:2 "In this genus it may be right to caution the student to place no reliance on the shape of the leaves or their pubescence, or suppression of the parts of the flower." To this we would add further, that neither can much reliance be placed upon the character of the inflorescence, since the differences between the peduncles being axillary or opposite, seem chiefly to depend upon different degrees of luxuriance.

3. Pemphis acidula.—The capsules burst by an irregular transverse fissure about the middle, with the lower portion more membranous than the upper, Forster describes them as having six valves, and Lamarck as opening transversely at the base.

"No sooner has a new reef become sufficiently elevated by the accumulation of sand upon its surface, but this plant is sure to be the first which takes possession of the soil."— C. Darwin.

4. Portulaca oleracea.—The specimen is in seed, tolerably luxuriant, and seems unquestionably to belong to this species; but there are some minute hairs in the axils, which is not generally the case, and not characteristic of the section to which it belongs.

5. Guilandina Bonduc.—The specimen is only in bud. "Grows only on one islet."—C. Darwin.

I have named this species in honour of Mons. Gaudichaud the founder of the genus Urera, who has attempted to group the species of this much-neglected order in the volume devoted to the botany of the 'Voyage de l'Uranie.'1 The only described species to which it seems to approach is the Urtica ruderalis of Forster, but a comparison with his original specimen in the British Museum has shown me that it is perfectly distinct.

The single specimen brought home by Mr. Darwin consists of part of an herbaceous stem about seven inches long, belonging apparently to a perennial. From each of the axils of the two lowermost leaves proceeds a short branch, and from each of seven or eight others spring divaricate branching cymose panicles about four inches long. The petiole and limb of the largest leaf are each four inches long, and the latter is 2 1/2 inches broad. The inferior panicles produce male flowers on their lower branches and female on their upper; but the superior bear female only. Male flowers crowded in small heads at the extremities of the short branches, their calyx deeply 5-partite (fig. 1.); stamens 5. Female flowers smaller than the males, their calyx of three sepals, or rather of two sepals and an external bract (fig. 2.); the pistil solitary, ovary ovate and slightly oblique (fig. 3.); the stigma crowned with a ferruginous tuft of hair inclining to one side. The ripe pericarp obliquely-ovate or gibbous (fig. 4.) containing one erect sessile exalbuminous seed (fig. 5.) with the embryo inverted (fig. 6).

There are two specimens of this, each about a foot long, with the terminal spike on one of them six inches, on the other not two.Largest leaves three inches. It is difficult to decide whether this ought to be considered a new species or only a variety of argentea.

Decaisne considers argentea and aspera to be identical. The very variable character of the herbage prevents our laying any great stress upon the shape of the leaf, length of the spike, or degree of pubescence. In these respects our plant comes within the character of argentea given by Decaisne in the 'Flora Timorensis.'

On comparing the several parts of the flower with those of another specimen of argentea, brought by Mr. Darwin from the Cape-de-Verd Islands, I find several remarkable differences, which I may here describe.

Comparison of the parts of the flower in specimens of Achyranthes argentea from the Keelings and Cape-de-Verd. Plate XI. where K. means Keeling, and V. Cape-de-Verd Islands.

KEELING.

CAPE-DE-VERD.

Fig. 7. Bract. Auricles at base, about

About one third the length.

half the length of'the bract.

8. Sepal.

9. Stamens and pistil.

10. Stamen, with part of connecting membrane.

Anther. Elliptic-oblong, equal to free portion of filament.

Subrotund and much shorten.

Fringed lobes (from abortive stamens?) with few and regular incisions.

Incisions numerous and very irregular.

11. Pistil. Ovary ob-ovato-globose, depressed, with the style three times as long.

Ob-ovato-cylindrical, with the style

half as long.

The position and form of the ovule is also marked on the figures.

9. Boerhavia diffusa.—After an attentive examination of Mr. Darwin's specimens, I cannot detect sufficient differences to class them under more than one species, though he had himself concluded, from certain peculiarities in their habit whilst growing, that they must belong to three. These three forms, which I consider to be varieties of the diffusa of Decaisne's Herb. Timor., have each long, weak, straggling, terete branches, clothed with close scattered pubescence, except on the older parts, which are glabrous. The leaves are stalked

and fleshy, modifications of ovate and repand. The flowers in small heads, which themselves are arranged in dense umbels, with long axillary peduncles alternately disposed among the uppermost parts of the branches.

Var. a. Stoutest in habit, and with the largest leaves, the lowermost of which have their limb an inch long, with peduncles of half an inch; all are pedunculate, ovato-rotund, often slightly sub-cordate, much paler beneath. Stamens 2—3; young fruit ob-clavato-fusiform.

Var. β. Branches more than three feet long. Leaves rather smaller and darker on each side, generally more acute, the uppermost nearly or quite sessile. Seems to be B. diandra of Bur. Fl. Ind., tab. 1. fig. 1. Stamens 2—4, alternate with the segments of the calyx; anther with two globose cells, which, with the filaments, are pilose. Ovary oval, but in the young fruit becomes fusiform and angular, with glandular hairs. Stigma peltate. A toothed annulus round the calyx was noticed in one specimen. Three or four bracts.

"Grows upright and untidy, and is the commonest weed, growing everywhere."—C. Darwin.

Var. γ. Branches a foot and a half long. More stunted, with fewer, smaller, and more fleshy leaves. Stamens 2—3.

"Grows close to the ground, and is abundant on one spot within ten or twelve yards of the sea, where it was pointed out to me as possessing an esculent root, and considered to be quite distinct from var. β."—C. Darwin.

A specimen of the root was preserved, and consists of long wiry branches, which do not appear to have been ever very succulent.

10. Scavola Kœnigii.—The leaves are seven inches long and three broad, quite glabrous; the apex slightly retuse and the margin somewhat repand. Segments of the calyx subulate and glabrous. Corolla with the base of the tube slightly villose within, the segments of the limb lanceolate and glabrous. Cupula of the stigma very pilose within. This specimen appears to be more glabrous than usual, whilst S. sericea (of which I have specimens from Macao in China) differs from the more usual state of S. Kœnigii chiefly in being more decidedly pubescent.

12. Cordia orientalis.—"The settlers have named this Keeling-teak, because it furnishes them with excellent timber. They have built themselves a vessel with it. A large tree, abounding in some of the islands, very leafy, with scarlet flowers; but only a few blossoms were expanded at the time, and they easily fell off."—C. Darwin.

14. Dicliptera Burmanni, var.?—Some of Nees von Esenbeck's species (in Wallich's Pl. As. Rar. vol. iii. pp. Ill, 112,)1 run so closely together, that it is difficult to say whether he would have referred these specimens to Burmanni or not. I will here subjoin a full description of them, and it may serve future observers in either extending the character of Burmanni, or of reuniting with it some of the other forms now considered to be distinct species, but formerly combined under the name of Justicia chinensis.

15. Ochrosia parviflora.—This is unquestionably the Cerbera parviflora of Forster Prod. n. 121., as Mr. Brown showed me by comparison with the original specimens in the British Museum; but Dr. Hooker's C. parviflora, in Beechy's Voyage, p. 90,1 is certainly a distinct species, as I have ascertained by an examination of his specimens, kindly forwarded to me for comparison with Mr. Darwin's. Dryander,2 in the Linn. Trans., vol. ii. p. 227, asserts that he had compared Forster's specimens of C. parviflora with Commerson's3 of Ochrosia borbonica, and found them to be the same species. This has been since disputed. I have specimens of Och. undulata from Mauritius, labelled by Bojer4 as the "Bois jaune" of that island, which appears to identify that species with Jussieu's5Och. borbonica. There is some obscurity in the descriptions hitherto given of the fruits of Cerbera, Ochrosia and Tanghinia, and I had hoped to have been able to have inserted here my own observations on them, but I must defer them until I have time to clear up one or two points about which I am doubtful. I should feel much obliged in the mean time to any botanist who can furnish me with specimens of the fruit of these, or any allied genera, for dissection. Mr. Darwin's specimens were accompanied by the following note: "Forms straight handsome trees, with smooth bark, which are commonly dispersed two or three together. The fruit is bright green, like that of the walnut." Two specimens of this fruit were brought home, and though Mr. Darwin feels confident that he gathered them, and, as he believes, from the same tree which bore flowers at the time, yet it has been supposed that they must belong to a species of Cerbera, and not to an Ochrosia which this plant seems to be; and I shall therefore defer their description for the present, merely intimating that I believe them to be identical with the Cerbera platysperma of Gærtner. The following is a detailed description of the flowering specimens from Keeling.

16. Panicum sanguinale, var. ?.—I quote this species with doubt, because the only specimen has the spikes half starved and the spikelets not fully matured. It has much the habit of P. pruriens of Trinius1 Gram. Icones, with a trailing stem of four feet, but the glumes have the relative proportions ascribed to P. sanguinale, and the margins of the superior one are very hirsute. There are thirteen spikelets, but three or four towards the summit are quite abortive. They are arranged in two whorls of four in each; one is below the lowest whorl, and the other four are scattered between the two whorls. As Decaisne gives P. sanguinale as a Timor plant, the present may the more probably be only a form of this.

Mr. Brown showed me a single specimen of this grass among Forster's specimens of Lepturus repens in the British Museum, and the general resemblance which it may be considered to bear to that plant has induced me to give it the specific name of lepturoide. It departs from the generic character of Stenotaphrum, given in Kunth's Agrostographia,2 in not having the spikelets arranged unilaterally, and in the rachis of the spike being terete or very nearly so; but in all essential points it is truly a Stenotaphrum, as the following detailed description will be sufficient to show.

18. Lepturus repens.—"Occurs in salt places, in the interior of the islands."— C. Darwin.

19. Cocos nucifera.—Although no specimen of this was brought home, yet as the Keelings are also called Cocos Islands, and as they have been recently colonized for the express purpose of trading in the oil and fruit, we may safely assert it to be abundant.

20. Hypnum rufescens.—The specimens were submitted to Dr. Hooker, who remarks, "In a very indifferent state certainly, but I think it may safely be referred to H. rufescens, Hooker and Arnott, of Bot. of Beechy's Voyage, page 76, t. 19, It is in a younger and greener state."

21. Polyporus lucidus.—These were sent to Mr. Berkeley with a query, whether they might not be P. australis; to which he replies, "I have no doubt your fungus is P. lucidus. I have before me specimens of precisely the same thing from Mauritius, together with a distinct variety resembling, I should imagine, P. australis. That, however, is a perennial species, and the substance is very hard; whereas your plant is at most biennial, and the substance soft and spongy."